April 6, 2014 5:16pm EDTApril 6, 2014 1:40pm EDTJameson Taillon, the team's top pitching prospect, will have Tommy John surgery and miss the entire season, the team announced Sunday.Jameson Taillon(AP Photo)

Dr. David Altchek will perform the surgery in New York at a date to be determined.

Taillon, 22, began feeling pain in his elbow with two weeks remaining in spring training after being assigned by the Pirates to their minor league camp. Doctors prescribed two weeks of rest, but Taillon again felt pain when he tried to throw again.

While Taillon does not have a fully torn ligament, Altchek felt it was compromised to the point where surgery was necessary. Taillon will be out 12 to 18 months.

"Taillon’s 2013 season was a bit disappointing by the lofty expectations put upon the second overall pick in the 2010 draft but tempered by the reality that the big Texan was a 21-year-old pitching in Double-A and Triple-A," Allan Simpson and David Rawnsley wrote in SN's 2014 Baseball Yearbook. "He went 5-10 with a 3.73 ERA in 147 innings between the two levels. Taillon has two easy plus pitches in his lively mid-90s fastball and power low-80s curveball."